Power control system with improved thermal performance

ABSTRACT

An electrical power distribution system is provided. The electrical power distribution system includes one or more power distribution cards comprising a first portion and a second portion. The electrical power distribution system further includes one or more power switching components coupled to the first portion of one of the one or more power distribution cards. The electrical power distribution system further includes one or more control devices configured to control operation of at least one of the one or more power switching components. Each control device is coupled to the second portion of one of the one or more power distribution cards. The first portion of each power distribution card is separated from the second portion, such that, during operation of the power distribution card, the control devices operate at a lower average temperature than the power switching components.

FIELD OF INVENTION

The present subject matter relates generally to electrical powerdistribution systems.

BACKGROUND

Electrical systems associated with aircraft and other vehicles may havea plurality of electrical subsystems, each having one or more electricalpower distribution systems. Such electrical power distribution systemsmay include one or more power distribution cards mounted vertically tothe electrical system in a rack-like manner. Such power distributioncards may include one or more printed circuit boards having one or moreswitching devices configured to control current flow to a loadassociated with the electrical system. The printed circuit boards mayfurther include one or more control devices configured to controloperation of at least one switching device.

Conventional power distribution cards may have a layout configurationwherein one or more switching devices are located in close proximity toa corresponding control device. For instance, a switching device and acorresponding control device may be coupled to the power distributioncard as part of a prefabricated solid state power controller (SSPC)“module.” FIG. 1 depicts an example conventional power distribution card100. As shown, card 100 includes SSPC blocks A-L, routing device 102,and card controller 104. Card 100 further includes connector 106configured to connect card 100 to an electrical system. Each SSPC blockA-L can be associated with one or more electrical subsystems. Inparticular, each SSPC block A-L can be configured to regulate currentflow to a load associated with the corresponding electrical subsystem.As shown, each SSPC block A-L includes two power switching devices (e.g.power FETs), a current sensor, and control logic located in closeproximity to each other.

During operation of card 100, the configuration of the SSCP blocks A-Lcan provide a generally even temperature distribution across card 100.Heat dissipation associated with the power FETs may be proportional tothe square of the load current, while heat dissipation associated withthe control logic may remain generally constant. Accordingly, when theload current associated with the power FETs is a high load current, theheat generated by the current flow will be much greater than thatgenerated by the relatively low power control logic. In this manner, thecontrol devices may experience an increased local temperatureenvironment, which may reduce the reliability or cause unpredictablebehavior in the control devices. For instance, if the average operatingtemperature of the control logic exceeds the specified maximum operatingtemperature of the control logic, the control logic may fail and/or actin an unpredictable manner.

BRIEF DESCRIPTION

Aspects and advantages of the present disclosure will be set forth inpart in the following description, or may be learned from thedescription, or may be learned through practice of the examplesdisclosed herein.

One example aspect of the present disclosure is directed to anelectrical power distribution system associated with an electricalsystem for an aircraft. The electrical power distribution systemincludes one or more power distribution cards. Each power distributioncard comprises a first portion and a second portion. The electricalpower distribution system further includes one or more power switchingcomponents. Each power switching component is coupled to the firstportion of one of the one or more power distribution cards. Theelectrical power distribution system further includes one or morecontrol devices. Each control device is configured to control operationof at least one of the one or more power switching components. Eachcontrol device is coupled to the second portion of one of the one ormore power distribution cards. The first portion of each powerdistribution card is separated from the second portion, such that,during operation of the power distribution card, the control devicesoperate at a lower average temperature than the power switchingcomponents.

Another example aspect of the present disclosure is directed to a powerdistribution card associated with a power distribution system. The powerdistribution card includes one or more power switching components. Eachpower switching component is coupled to a first portion of the powerdistribution card. The power distribution card further includes one ormore control devices configured to control operation of at least one ofthe one or more power switching components. Each control device iscoupled to a second portion of the power distribution card. The firstportion of the power distribution card is separated from the secondportion, such that, during operation of the power distribution card, thecontrol devices operate at a lower average temperature than the powerswitching components.

Yet another example aspect of the present disclosure is directed to anelectrical system associated with an aircraft. The electrical systemincludes one or more power distribution systems comprising one or morepower distribution cards. Each power distribution card includes one ormore power switching components. Each power switching component iscoupled to a first portion of one of the power distribution cards. Eachpower distribution card further includes one or more control devicesconfigured to control operation of at least one of the one or more powerswitching components. Each control device is coupled to a second portionof one of the power distribution cards. The first portion of each powerdistribution card is separated from the second portion, such that,during operation of the power distribution card, the control devicesoperate at a lower average temperature than the power switchingcomponents.

Variations and modifications can be made to these example aspects of thepresent disclosure.

These and other features, aspects and advantages of various exampleswill become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateaspects of the present disclosure and, together with the description,serve to explain the related principles.

BRIEF DESCRIPTION OF THE DRAWINGS

Detailed discussion of embodiments directed to one of ordinary skill inthe art are set forth in the specification, which makes reference to theappended figures, in which:

FIG. 1 depicts a conventional power distribution card associated with apower distribution system according to example embodiments of thepresent disclosure;

FIG. 2 depicts an overview of a power distribution card according toexample embodiments of the present disclosure; and

FIG. 3 depicts an overview of a power distribution card according toexample embodiments of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

Example aspects of the present disclosure are directed to electricalpower distribution units having improved thermal performance. In someimplementations, the power distribution units may be associated with anelectrical system in an aircraft or other vehicle. It will beappreciated that such power distribution units may be implemented withinvarious other suitable environments and/or applications withoutdeviating from the scope of the present disclosure. For instance, eachelectrical power distribution unit can include a plurality of powerdistribution cards. Each power distribution card can include one or morepower switching devices, such as one or more metal-oxide-semiconductorfield-effect transistors (MOSFETs). The power switching devices can beconfigured to regulate current flow to a load associated with theelectrical system. Each power switching device can have an associatedcontrol device configured to control operation of the power switchingdevice.

In some implementations, each power distribution card can include anupper portion and a lower portion. The upper and lower portions can beoriented such that, when the power distribution cards are mounted orotherwise connected to the electrical system of the aircraft or othervehicle, the upper portion is located above the lower portion. Forinstance, the power distribution cards can be mounted to the electricalsystem in a vertical manner in a rack or box configuration, such thatthe upper portion is located above the lower portion. The powerdistribution cards can be configured such that the power switchingdevices are located on the upper portion of the power distribution cardand the control devices are located on the lower portion of the powerdistribution card. In this manner, the power switching devices can bespatially separated from the control devices, thereby reducing theaverage operating temperature of the control devices relative to that ofthe power switching devices.

In particular, in some implementations, heat dissipation of the powerswitching devices can be proportional to the square of the load currentflowing through the power switching devices, while the heat dissipationof the control devices can remain constant. In this manner, at higherload currents, the majority of heat dissipation can originate from thepower switching devices, which also generally have a higher operatingtemperature tolerance than the control devices. By separating the powerswitching devices from the control devices, such that the powerswitching devices are located on the upper portion of the powerdistribution card and the control devices are located on the lowerportion of the power distribution card, the average operatingtemperature of the control devices can be lower than that of the powerswitching devices during normal operation of the electrical powerdistribution system. In this manner, operating the components coupled tothe upper portion of the power distribution card at a higher temperaturecan provide a greater temperature difference between the upper portionof the power distribution card and the environmental temperature. Suchincreased temperature difference can increase the heat flow rate and/orthe heat dissipation capability of the system, which can lead toincreased efficiency of the operation of the control devices.

In some implementations, the control devices can be configured tocontrol operation of one or more power switching devices based at leastin part on the current flowing through the power switching devices to aload associated with the electrical system. For instance, the powerdistribution card can further include one or more current sensors, eachassociated with one or more power switching devices. The current sensorsmay be included on the upper portion of the power distribution card. Thecurrent sensors can be configured to monitor current flow through thepower switching device(s) and to provide a signal indicative of thecurrent to the control device associated with the power switchingdevice(s). The control device can compare the signal indicative of thecurrent to a predetermined current threshold, and control operation ofthe power switching device(s) based at least in part on the comparison.For instance, if the signal indicative of the current is greater thanthe current threshold, the control device can provide one or morecontrol signals to the power switching device(s) causing the powerswitching device to “turn off,” thereby restricting or eliminatingcurrent flow through the power switching device(s). It will beappreciated that the control devices can be further configured toimplement various other control tasks or functions, such as forinstance, various functions relating to monitoring, switching,communications, and/or protection.

Each power distribution card can include one or more printed circuitboards. For instance, in some implementations, a power distribution cardcan include only a single printed circuit board, such that the upperportion and lower portions of the power distribution card are separatepartitions or regions of the same printed circuit board. In someimplementations, the upper and lower portions of the power distributioncard can be made of different materials. For instance, the upper portioncan be made from a material that is able to tolerate higher temperatures(e.g. ceramic), and the lower portion can be made from a differentmaterial that is not able to tolerate such high temperatures (e.g. FR4).In this manner, the power distribution card may include a single printedcircuit board made up of two or more different materials (e.g. a hightemperature material and a low temperature material). As anotherexample, the power distribution card may include two or more printedcircuit boards, each made of a different material.

In implementations wherein two or more printed circuit boards are used,a first printed circuit board may correspond to the upper portion of thepower distribution card, and a second printed circuit board maycorrespond to the lower portion of the power distribution card. In suchimplementations, the two or more printed circuit boards may be connectedvia an interboard connection device. The interboard connection devicemay include board-to-board connectors, flexible printed circuits withdiscrete wires, and/or various other suitable connection mechanisms.

The electrical power distribution system may use passive coolingtechniques, and/or active cooling techniques. For instance, the powerdistribution cards may rely solely on natural air convection todissipate heat produced by the distribution system. In someimplementations, one or more power distribution cards may includevarious suitable heat dissipation devices, such as one or more heatsinks, cold wall heat sinks, chimney structures, forced air devices,and/or various other suitable heat dissipation devices. In someimplementations, thermal insulation may be provided between the upperand lower portions of the power distribution cards.

With reference now to the figures, example aspects of the presentdisclosure will be discussed in more detail. For instance, FIG. 2depicts an overview of an example power distribution card 200 accordingto example embodiments of the present disclosure. Similar to card 100 ofFIG. 1, card 200 includes a plurality of switching devices (e.g. powerFETs), each having a corresponding current sensor and control logic. Insome implementations, the switching devices can be silicon carbide powerFETs, gallium nitride power FETs, or other switching device. Inparticular, card 200 includes FET blocks A-L, each having correspondingcontrol logic A-L. Control logic A-L can include various suitablecomponents or devices including, for instance, one or more processingdevices, amplifiers, comparators, isolators, and/or other componentsconfigured to implement various control functions associated with thecorresponding power FETs. Card 200 further includes routing device 206,card controller 208, and connector 210. Connector 210 can be configuredto connect card 200 to an electrical system associated, for instance,with an aircraft or other vehicle. FET blocks A-L each include two powerFETs and a current sensor configured to monitor a load currentassociated with the power FETs. It will be appreciated that the numberof FETs (e.g. FET blocks and/or FETs per FET block) depicted in FIG. 2is for illustrative purposes only and that various other suitablenumbers of FETs can be used without deviating from the scope of thepresent disclosure. As shown, card 200 includes an upper portion 202 anda lower portion 204. Dashed line 212 provides an illustrative indicationof the location of the divide between upper portion 202 and lowerportion 204. FET blocks A-L are located in upper portion 202, whilecontrol logic A-L are located in lower portion 204.

As indicated above, during operation, such power FETs may generate moreheat than control logic A-L. Further, the power FETs and current sensorsare generally tolerant of higher temperatures, while control logic A-Lmay not be tolerant of such high temperatures. For instance, controllogic A-L may have a maximum specified operating temperature of about125 degrees Celsius, while the power FETs may be rated for a highertemperature. As used herein, the term “about,” when used in conjunctionwith a numerical value is intended to refer to within 40% of thenumerical value. It will be appreciated that various control logichaving various other suitable temperature ratings may be used withoutdeviating from the scope of the present disclosure. Configuring thecomponent layout of card 200 in such fashion (e.g. separating thecontrol logic from FET blocks A-L such that FET blocks A-L are locatedabove control logic A-L) can increase the air flow and thermalperformance associated with the electrical system and/or decrease theaverage operating temperature of control logic A-L, thereby improvingthe reliability and/or efficiency of control logic A-L.

It will be appreciated that, in some implementations, card 200 canfurther include various other suitable components or devices. Forinstance, card 200 can further include various resistors, capacitors,etc. Such additional components may be located on upper portion 202 ofcard 200.

In various implementations, card 200 may be configured to use passivecooling and/or active cooling techniques to dissipate heat. Forinstance, in implementations wherein active cooling techniques are used,card 200 may further include one or more associated heat dissipationdevices, such as one or more fins or other heat sink devices, chimneystructures, cold wall heat sinks, force air devices, etc. In addition,thermal insulation may be provided between upper portion 202 and lowerportion 204.

In some implementations, the location of components relative to card 200(e.g. upper portion 202 or lower portion 204) can be determined based atleast in part on a specified temperature rating associated with therespective components. For instance, in such implementations, componentscan be attached or coupled to upper portion 202 of card 200 if thecomponents have a specified maximum operating temperature above athreshold. Similarly, components can be attached or coupled to lowerportion 204 if they have a specified maximum operating temperature belowthe threshold. In this manner, components that have a lower temperaturetolerance may be separated from components that have a highertemperature tolerance, such that the high temperature components may beallowed to operate at a higher temperature than can be tolerated by thelow temperature components.

Card 200 can be made of various suitable materials. For instance, insome implementations, card 200 can be made of a material capable oftolerating high temperatures (e.g. ceramic). In some implementations,card 200 can be made of multiple materials. For instance, upper portion202 may be made of a high temperature material (e.g. ceramic), whilelower portion 204 is made of a lower temperature material (e.g. FR4). Insuch implementations, card 200 may be made from one printed circuitboard made from multiple materials.

As indicated above, in some implementations, a power distribution cardmay include multiple printed circuit boards. For instance, FIG. 3depicts an overview of an example power distribution card 300 accordingto example embodiments of the present disclosure. As depicted, card 300includes an upper printed circuit board 302 and a lower printed circuitboard 304. In particular, printed circuit board 302 can be a separateand distinct board from printed circuit board 304. The printed circuitboards 302, 304 can be connected using an interboard connection device306, such as one or more board-to-board connectors, or flexible printedcircuits and discrete wires. Printed circuit boards 302 and 304 may eachhave connectors 308 configured to connect the printed circuit boards tothe electrical system.

Printed circuit board 302 can correspond to upper portion 202 of card200 of FIG. 2. In this manner, printed circuit board 302 can include FETblocks A-L. As above, FET blocks A-L may include various components(e.g. power FETs, current sensors, various resistors, capacitors, etc.)that are capable of tolerating higher temperatures (e.g. temperaturesabove a threshold). In particular, as above, it will be appreciated thatthe number of FETs (e.g. FET blocks and/or FETs per FET block) depictedin FIG. 3 is for illustrative purposes only and that various othersuitable numbers of FETs can be used without deviating from the scope ofthe present disclosure. In this manner, components that generate a largeamount of heat and/or are able to tolerate high temperatures arepositioned near the top of card 300. Similarly, printed circuit board304 can correspond to lower portion 204 of card 200. Printed circuitboard 304 can include control logic A-L. As indicated above, suchcontrol components that make up control logic A-L may not be rated totolerate temperatures as high as the components that make up FET blocksA-L. In this manner, control logic A-L can be separated from FET blocksA-L, thereby maintaining a lower average operating temperature ofcontrol logic A-L during operation.

In some implementations, printed circuit board 302 may be made from afirst material and printed circuit board 304 may be made from a secondmaterial. For instance, printed circuit board 302 may be made from amaterial capable of tolerating temperatures above a threshold, whileprinted circuit board 304 may be made from a material rated for lowertemperatures. For instance, printed circuit board 302 may be made from aceramic material, while printed circuit board 304 may be made from FR4.In such implementations, the power FETs may be able to operate at ahigher temperature than can be tolerated by the material from whichprinted circuit board 304 is made.

Although specific features of various embodiments may be shown in somedrawings and not in others, this is for convenience only. In accordancewith the principles of the present disclosure, any feature of a drawingmay be referenced and/or claimed in combination with any feature of anyother drawing.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What we claim is:
 1. An electrical power distribution system comprising:one or more power distribution cards, each power distribution cardcomprising a first portion and a second portion; one or more powerswitching components, wherein each power switching component is coupledto the first portion of one of the one or more power distribution cards;and one or more control devices, each configured to control operation ofat least one of the one or more power switching components, wherein eachcontrol device is coupled to the second portion of one of the one ormore power distribution cards; wherein the first portion of each powerdistribution card is spatially separated from the second portion, suchthat, during operation of the power distribution card, the controldevices operate at a lower average temperature than the power switchingcomponents.
 2. The electrical power distribution system of claim 1,wherein at least one power distribution card comprises a first printedcircuit board and a second printed circuit board, such that the firstprinted circuit board comprises the first portion of the powerdistribution card and the second printed circuit board comprises thesecond portion of the power distribution card.
 3. The electrical powerdistribution system of claim 2, wherein the first printed circuit boardand the second printed circuit board are connected by an interboardconnection device.
 4. The electrical power distribution system of claim2, wherein the first printed circuit board is made from a first materialand the second printed circuit board is made from a second material. 5.The electrical power distribution system of claim 1, wherein each powerdistribution card comprises a single printed circuit board.
 6. Theelectrical power distribution system of claim 5, wherein the firstportion of the power distribution card is made from a first material andthe second portion of the power distribution card is made from a secondmaterial.
 7. The electrical power distribution system of claim 1,further comprising one or more current sensors coupled to the firstportion of the power distribution card, each of the one or more currentsensors configured to monitor a current flowing to a load through atleast one power switching component.
 8. The electrical powerdistribution system of claim 7, wherein each current sensor isconfigured to provide one or more signals indicative of the currentflowing to the load through the at least one power switching componentto a control device, and wherein the control device is configured tocontrol operation of the at least one of the one or more power switchingcomponents based at least in part on the signal indicative of thecurrent.
 9. The electrical power distribution system of claim 1, whereineach power distribution card is configured to be connected to theelectrical system in a vertical manner such that, when connected, thefirst portion of each power distribution card is located above thesecond portion of the power distribution card.
 10. The electrical powerdistribution system of claim 1, wherein at least one power distributioncard further comprises one or more heat dissipation devices.
 11. Theelectrical power distribution system of claim 10, wherein the one ormore heat dissipation devices comprise one or more heat sink devices,one or more chimney devices, one or more cold wall heat sink devices, orone or more forced air devices.
 12. The electrical power distributionsystem of claim 1, wherein thermal insulation is provided between thefirst portion of at least one power distribution card and the secondportion of the at least one power distribution card.
 13. The electricalpower distribution system of claim 1, wherein the one or more powerswitching components comprise metal-oxide-semiconductor field-effecttransistors.
 14. The electrical power distribution system of claim 13,wherein the metal-oxide-semiconductor field-effect transistors comprisesilicon carbide or gallium nitride metal-oxide-semiconductorfield-effect transistors.
 15. A power distribution card associated witha power distribution system, the power distribution card comprising: oneor more power switching components, wherein each power switchingcomponent is coupled to a first portion of the power distribution card;and one or more control devices configured to control operation of atleast one of the one or more power switching components, wherein eachcontrol device is coupled to a second portion of the power distributioncard; wherein the first portion of the power distribution card isseparated from the second portion, such that, during operation of thepower distribution card, the control devices operate at a lower averagetemperature than the power switching components.
 16. The powerdistribution card of claim 15, wherein the power distribution cardcomprises a first printed circuit board and a second printed circuitboard, such that the first printed circuit board comprises the firstportion of the power distribution card and the second printed circuitboard comprises the second portion of the power distribution card. 17.The power distribution card of claim 16, wherein the first printedcircuit board is made from a first material and the second printedcircuit board is made from a second material.
 18. The power distributioncard of claim 17, wherein the first material is a ceramic material, andwherein the second material is FR4.
 19. The power distribution card ofclaim 15, wherein thermal insulation is provided between the firstportion of the power distribution card and the second portion of thepower distribution card.
 20. An electrical system associated with anaircraft, the electrical system comprising: one or more powerdistribution systems comprising one or more power distribution cards,each power distribution card comprising: one or more power switchingcomponents, wherein each power switching component is coupled to a firstportion of one of the power distribution cards; and one or more controldevices configured to control operation of at least one of the one ormore power switching components, wherein each control device is coupledto a second portion of one of the power distribution cards; wherein thefirst portion of each power distribution card is separated from thesecond portion, such that, during operation of the power distributioncard, the control devices operate at a lower average temperature thanthe power switching components.